Methods and apparatus for the treatment of wells having multiple formations



1 6 25 0 7 [DRESS Maw-mm.

MLHHLIH HUUWI Feb. 28, 1961 c. c. BROWN 2,973,035 METHODS AND APPARATUS FOR THE TREATMENT 0F WELLS HAVING MULTIPLE FORMATIONS K Filed Nov. 2. 1954 9 Sheets-Sheet 1 ATTOR/VfYJ Feb. 28, 1961 c. c. BROWN METHODS AND APPARATUS FOR THE TREATMENT OF WELLS HAVING MULTIPLE FORMATIONS 9 Sheets-Sheet 2 Filed NOV. 2, 1954 f km C/cera C. Brow/7 INVENTOR.

y. WWW 2m KK/QMLL ATTOR/VfKS Feb. 28, 1961 c. c. BROWN METHODS AND APPARATUS FOR THE TREATMENT OF WELLS HAVING MULTIPLE F ORMATIONS 9 Sheets-Sheet 3 Filed Nov. 2, 1954 C/cero C. Brown INVENTOR.

BY fi e Z 2W flK/ ATTOR/VfYJ 1961 c. c. BROWN 2,973,035

METHODS AND APPARATUS FOR THE TREATMENT OF WELLS HAVING MULTIPLE FORMATIONS Filed Nov. 2, 1954 9 Sheets-Sheet 4 C/cero C. flrown INVENTOR.

1961 c. c. BROWN 2,973,035

METHODS AND APPARATUS FOR THE TREATMENT OF WELLS HAVING MULTIPLE FORMATIONS Filed Nov. 2, 1954 9 Sheets-Sheet 5 /2 I 70d /0 63b 63a (m l 7Z6 -63 26 l l t 1 a I I 220 V 1 22 C/cero C. Brown INVENTOR.

X, KKKWL A TTOR/VE YJ Feb. 1961 c. c. BROWN 2,973,035

METHODS AND APPARATUS FOR THE TREATMENT OF WELLS HAVING MULTIPLE FORMATIONS Filed Nov. 2, 1954 9 Sheets-Sheet 6 r I 7/1 W J I I C/ce/o C. Brown INVENTOR.

4/ I BY w ,KKM

ATTORNEYJ METHODS AND APPARATUS FOR THE TREATMENT OF WELLS HAVING MULTIPLE FORMATIONS 9 Sheets-Sheet 7 Filed NOV. 2, 1954 C/ce/o C B/OWH INVENTOR. Byfj W Z; M /%M 4Tf0/TWEYJ Feb. 28, 1961 c. 0. BROWN 2,973,035

METHODS AND APPARATUS FOR THE TREATMENT OF WELLS HAVING MULTIPLE FORMATIONS Filed Nov. 2, 1954 9 Sheets-Sheet 8 Feb. 28, 1961 c. c. BROWN 2,973,035

METHODS AND APPARATUS FOR THE TREATMENT OF WELLS HAVING MULTIPLE FORMATIONS Filed NOV. 2, 1954 9 Sheets-Sheet 9 Clce/"o C. Brown INVENTOR.

VAMMWMZZ A9 BY Z: W

A A ATTOR/VE y:

United States Patent METHODS AND APPARATUS FOR THE TREAT- MENT OF WELLS HAVING MULTIPLE FORMA- TIONS Cicero C. Brown, 2216 Campbell, Houston, Tex. Filed Nov. 2, 1954, Ser. No. 466,291

16 Claims. (Cl. 166-46) This invention relates to new and useful improvements in methods and apparatus for the treatment and completion of wells having multiple producing formations.

One object of this invention is to provide a new and improved method and apparatus for selectively treat ng one or more well formations in a continuous operation and without removing the apparatus from the well bore.

An important object of this invention is to provide a method and apparatus for the treatment of a well having multiple formations, wherein one formation may be initially treated and thereafter completed to cause the formation to produce well fluid therefrom, after which such formation may be closed ofl while a second formation is treated in a desired manner; all of the steps of the method being performed in a continuous manner and without the necessity of removing the apparatus from the well bore.

Another object of this invent-ion is to provide a new and improved method and apparatus for well completion which permits a plurality of well formations in a well bore to be properly treated and brought in, and which is so arranged that the same apparatus employed in the treatment and completion operations can be utilized for conducting the fluid to the surface of the well.

A particular object is to provide an improved method of treating and completing multiple producing formations in the same well bore which includes, lowering a pair of packers within a well bore and setting the lower packer above the lowermost formation, treating said lowermost formation and causing the same to produce well fluids, shutting off flow of well fluids at the lower packer, separating the packers and raising the upper packer and setting it above the next above producing formation, thereafter treating the second formation to cause it to produce well fluids, then reconnecting the packers and raising both packers to locate and set the lower packer above the second formation, and finally opening flow through the packers to produce the well fluids from both formations.

Still another object is to provide an improved well treating and completion apparatus which includes two packers having a releasable connection therebetween and a removable closure for selectively closing flow through the lower packer; said apparatus lending itself to the performance of various operations, such as acidizing, cementing, etc., and permitting the treatment and completion of any desired operation or series of operations in any desired sequence and with respect to any desired number of producing formations which may be present in the single well bore. 1

Another object of this invention is to provide a new and improved apparatus wherein a pair of packers are releasably connected together and suspended on a well pipe, the packers being operable separately by manipulation of the pipe for setting one packer at a time, said packers also being separable from each other by a manipulation of the well pipe to disconnect the releasable conice 2 nection therebetween, whereby the packers may be located in anydesired spacing relative to each other.

A further object of this invention is to provide in a well treating and completion apparatus, an improved well packer which is adapted to be operated to either set or release the same within a well pipe by manipulation of the supporting pipe and without any lefthand rotation of the pipe string.

A still further object of this invention is to provide a new and improved closure plug which is adapted to be lowered into a well pipe by pumping or otherwise for automatically latching same therein at a predetermined point in the well pipe for ,closing off upward fluid flow from the area below the plug through the pipe.

The construction designed to carry out the invention will be hereinafter described, together with other features thereof.

a The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown, and wherein:

Figure 1 is a schematic view illustrating the apparatus of this invention in position in a well bore for treating the lower well formation.

Figure 2 is a schematic view illustrating the apparatus in position for treating the upper formation after the lower formation has been closed by a plug.

Figure 3 is a schematic view illustrating the apparatus of this invention in a position above the second formation previously treated. Figure 4 is a schematic view illustrating the treatment of a third formation in the well bore while maintaining the two lower formations which have been previously treated in a closed condition.

Figures 5A, 5B, 5C, 5D together illustrate the preferred apparatus of this invention, partly in section and partly in elevation.

Figures 6A, 6B, 6C and 6D are used, partly in section and partly in elevation, which together illustrate the apparatus illustrated in Figures 5A-5D, but illustrating same with the packers in a set position.

Figures 7A and 7B are views, partly in elevation and partly in section, which illustrate the preferred plug construction used in this invention connected with a means for retrieving same from the well bore.

Figure 8 is a sectional'view illustrating the doublethreaded coupling member of this invention.

Figure 9 is a horizontal sectional view taken on line 99 of Figure 5D.

Figure 10 is a horizontal sectional view taken on line 10-40 of Figure 5D.

Figure 11 is a horizontal sectional view taken on line 1l-11 of Figure 5C.

Figure 12 is a view, partly in elevation and partly in section, illustrating a modified upper packer construction for the apparatus of this invention.

Figure 13 is a horizontal sectional view taken on line 13'l3 of Figure 12.

Figure 14 is a horizontal sectional view taken on line 1414 of Figure 12.

Figure 15 is an elevation illustrating a portion of the connecting means for the packer of Figure 12.

packer A is connected to an upper packer B through a a tubing or pipe string T. The packers A and B are adapted to be set into anchoring engagement with the casing W and released therefrom by a manipulation of the tubing string T from the surface of the well bore. Also, the releasable connection C is adapted to be released and re-engaged by a manipulation through the tubing T. For closing E fluid flow through the lower packer A, a plug P is employed which is adapted to be lowered downwardly by pumping or otherwise through the tubing string for automatically seating in a latched position at the upper end of the lower packer A. With the apparatus of this invention, a well having multiple formations, such as the well formations X, Y and Z illustrated in Figures 1-4, can be selectively treated and/or produccd without removing the apparatus of this invention from the well casing W.

In Figures 5A, 5B, 5C and 5D, the preferred construction of the apparatus of this invention is illustrated in detail. The lower packer A is shown in Figure 5D,

I wherein a plurality of radially expansible pipe gripping slips are disposed in a slip housing or carrier 11 which is substantially cylindrical in shape and which has a plurality of circumferentially spaced openings 11a through which the plurality of slips 10 are adapted to move radially for moving into anchoring or gripping engagement with the well casing W. The slips 10 are urged radially outwardly into such anchoring engagement with the casing W by a slip cone or expander 14 which has a downwardly and inwardly inclined external surface 14a which coacts with the inner downwardly and inwardly inclined surface 10a of the slips 10'. The upper end of the slip cone 14 has connected therewith a resilient seal cup or packing member 15 which is formed of rubber or other resilient material and which has associated therewith a plurality of auxiliary anchor segments 16 which have gripping teeth 16a thereon for engaging the casing W upon a lateral or radial movement of the packing member 15 outwardly. The anchor segments 16 are usually formed integrally with the packing member 15 by molding a portion thereof together with the rubber packing member 15, but it will be appreciated that any suitable means for attaching the anchor segments 16 to the packing member 15 will sutlice, as long as the anchor segments 16 are adapted to move radially outwardly upon an expansion of r the packing member 15 outwardly.

A lower seal cup or packing member 18, which is also formed of rubber or other resilient material, is carried from the lower end of the slip housing 11 with an adaptor 19 therebetween. The packing member 18 has a plurality of radially expansible auxiliary anchor segments 20 which are adapted to move into gripping contact with the well casing W upon a radial expansion of the packing member 18 into sealing engagement with the casing W. The usual friction springs 12 are mounted on the slip housing 11 for resisting longitudinal and rotational movement of the housing 11.

A mandrel 22 extends through the bore of the packer A and it has a set of lower threads 23 formed thereon and a set of upper threads 24 formed thereon. During the lowering of the apparatus into the well casing W, the threads 23 are in threaded engagement with a doublethreaded nut or coupling 25 (Figure 5D and 8), which is formed with both right and lefthand internal threads. The coupling 25 is formed in a. plurality of arcuate segments cut or otherwise formed from a cylinder, which are retained in the cylindrical shape by resilient rings 26 which extend around the outside of the coupling 25 and urge all of the segments thereof inwardly. However, it will be evident that the segments of the coupling 25 are adapted to slide radially outwardly so as to separate from each other and for guiding such movement and preventing rotation of the coupling 25 with respect to the adaptor 19, each segment of the coupling 25 has a groove or keyway 25a intowhich a lug or key 27 extends. The adaptor 19 is provided with a sufiicient recess 19a so as to permit a limited radial expansion of the segments of the coupling 25 against the inward urging of the resilient members 26.

The threads 23 are preferably buttress type threads and are constructed with a substantially laterally extending lower surface 23a and an inclined upper surface 23b whereby the threads are adapted to be rotated for release of the threads in a downward direction with respect to the coupling 25, but are adapted to slide upwardly into the coupling 25 without rotation by expanding the segments of the coupling 25 outwardly until the threads 23 I finally seat in the threads of the coupling 25. Preferably the threads 23 are righthand threads so that a righthand rotation of the mandrel 22 (as viewed from the top of Figure 5B) will result in a downward movement of the mandrel 22 with respect to the coupling 25 so as to effect the release of the threads 23 from the coupling 25.

The threads 24 are also buttress type threads and are formed in an opposite manner from threads 23 and the upper surfaces thereof are laterally extending substantially flat surfaces 24:: while the lower portion 24b is inclined and preferably the threads 24 are lefthand threads. With such construction of the threads 24, after the threads 23 have been disengaged and passed below the coupling 25, the threads 24 can be forced into the coupling 25 by a non-rotative longitudinal movement of the mandrel 22. The inclined surfaces 24b effect an expansion of the segments of the coupling 25 so that the threads 24 actually engage within the lefthand threaded portion of the coupling 25, but without the necessity for rotating the mandrel 22 relative to the coupling 25.. When it is desired to move the mandrel upwardly relatvie to the coupling 25 after the threads 24 are seated in the coupling 25, such upward movement can be obtained by a rotation of the mandrel 22 to the right. Thus, the release of the threads 23 is etfected by a rotation to the right and a release of the threads 24 from the coupling 25 is effected by a rotation to the right. It will be evident, of course. that if the direction of the threads 23 and 24 are changed so that the threads 23 are lefthand and the threads 24 are righthand, then the release of both sets of threads 23 and 24 would be effected to the left, but in the usual practice, the rotation would preferably be to the right. Inany event, the release of the sets of threads 23 and 24 is in the same direction and is effected by a rotation of the mandrel 22 which, as will be explained, is controlled from the surface of the well through the rotation of the tubing string T.

For retaining the slip expander 14 in a raised position so as to prevent a premature setting of the slips 10, the mandrel 22 has an annular shoulder 28 which is adapted to engage one or, more pins 29 which are mounted on the cone 14 and extend radially inwardly into the bore thereof. Thus, with the threads 23 engaged in the coupling 25 and the shoulder 28 in contact with the pins 29, the slip expander is prevented from relative longitudinal movement with respect to the slips 10 to thereby prevent premature setting of the slips 10. The pins 29 also coact with the annular shoulder 28 to prevent a movement of the threads 23 past the coupling 25 upon a non-rotative longitudinal movement of the mandrel upwardly for the re-engagement of the threads 23 with the coupling 25. For preventing the movement of the threads 24 below the coupling 25 upon a non-rotative longitudinal lowering of the mandrel 22 with respect to the coupling 25, an annular radially extending shoulder 30 is provided on the mandrel 22 for abutment with pins 29 (Figure 6D).

The mandrel 22 is provided with annular enlarged portions 22a and 22b which are adapted to engage in sealing contact with the seal rings 32 and 33 which are formed of rubber or other resilient material and which prevent a bypass of fluid around themandrel when in the set position. (Figure 6D). It should also be noted that I It bypass ports 34 and 35 are provided in the lower packer A for providing an equalizing fluid or bypass of fluid above and below the upper and lower packing members 15 and 18 so as to prevent their being urged radially prior to the setting of the slips 10. Thus, when the enlarged portions 22a and 22b of the mandrel 22 are in sealing engagement with the seal rings 32 and 33, the ports 34 and 35 are effectively closed so that the fluid pressure above and below the packing members 15 and 18 acts to urge same outwardly into their sealing engagement with the casing W. Also, the auxiliary anchor segments 16 and 20 are urged outwardly with the radial movement of the packing members 15 and 18.

In Figures 5A and 5B the upper packer B is illustrated in detail, wherein a plurality of pipe gripping slips 40 are illustrated as being mounted upon resilient or spring members 41. The spring members 41 are all connected to a ring 42 (Figure 5B) and they extend downwardly and are bowed outwardly at 41a for constant frictional engagement with the inside of the well casing W. The lower ends of the springs 41 are connected to a lower ring 43 which also carries upwardly and inwardly extending latch arms 44. The latch arms 44 engage beneath an annular latch ring 45 which is welded or otherwise secured to the mandrel 46, the latter extending through the entire length of the packer B.

Above the slips 40 and surrounding the mandrel 46, there is located a sleeve 47 which is spaced from the mandrel 46 and which has its upper end connected to an adaptor ring 48. An annular packing or sealing element 49 is connected to the lower end of the annular anchor segments 50 are attached'to the packing or sealing member 49 and are urged radially outwardly into gripping contact with the well casing W when the sealing or packing element 49 is radially compressed or expanded into sealing contact with the well casing W. Retaining dogs 51 are mounted at the lower end of the packing element 49 so as to permit the relative outward expansion of the element 49 with respect to a cone or slip expander 52 located therebelow. Fluid ports 47a, 47b and 470 are provided in the internal retaining sleeve 47 to permit fluid equalization around the packing or sealing element 49. a

At the upper end of the collar 48, an expansible nut 53 is provided which is formed in a plurality .of segments and which is retained in an inward or cylindrical condition by a resilient ring 54 surrounding the segments of the nut 53. The nut 53 is prevented from rotating relative to the collar 48 by a pin or screw 55 which extends into a slot 56 for each of the segments of the nut 53. It will be observed that the nut 53 is capable of being expanded into the annular recess area 48a. The mandrel 46 has a threaded section 57 which is adapted to automatically engage with the internal threads of the nut 53 upon a non-rotative downward movement of the mandrel 46 with respect to the adaptor or collar 48, but for releasing the threaded portion 57 from the nut 53, the mandrel 46 must be rotated preferably to the right.

When the threaded portion 57 and the nut 53 are connected, and the latch arms 44 are positioned below the annular latch ring 45,. the slip cone 52 is spaced from the slips 40 (Figure 5A) so that the slips 40 are not set into gripping engagement with the well casing W. Neither is the packing element 49 in sealing contact with the well casing W. For effecting a release of the latch arms 44 from their position below the latching ring 45, a release collar or sleeve 60 is provided at the lower end of the mandrel 46 and such sleeve 60 normally rests upon the upper .end of a coupling 61 at the lower end of the mandrel 46. Openings 60a are provided in the sleeve 60 for fluid circulation to provide the equalization around the sleeve 60 so that it will not be affected by the fluid pressures in the well. When it is desired to move the latch arms 44 upwardly past the annular ring 45, the tubing T and the mandrel 46 are raised, and due to the frictional engagement of the bowed portion 41a of the springs 41; the slips 40 do not move upwardly with the mandrel 46. The upward movement of the mandrel 46 is continued until the 1.1 per end 60b of the release sleeve 60 contacts the lower annular edge of the ring 45 which thus forces the latch arms 44 radially outwardly so that they ride or contact the outer surface of the sleeve 60. Thereafter, the tubing T and the mandrel 46 outwardly by the latch sleeve 60 a distance equal to the outside diameter of the ring 45, the latch ring 45 can move through or below the arms 44. After the ring has thus passed below the latch arms 44, it will be evident that the cone 52- and the parts connected thereabove to the mandrel 46 can be carried downwardly relative to the slips 40 so that the cone '52 is brought downwardly for bringing its inclined surface 52a into sliding engagement with the inside surface 40 of the slips 40 to thereby radially expand the slips 40 into gripping engagement with the well casing W. Once the slips 40 are thus set, the downward travel of the cone 52 is stopped and therefore continued lowering of the mandrel 46 applies a downward force to the upper end of the packing orsealing element 49 to radially expand or compress same into sealing contactwith the well casing W. The packer B will thus remain inthe set position (Figures 6A and 6B) by the maintaining of a portion of the tubing weight thereon. It will also be evident that the auxiliary anchor segments are moved into gripping engagement with the well casing W as the sealing or packing element 49 is expanded (Figure 6A).

The packer B is released by a pull upwardly on the tubing T and the mandrel 46 to separate the slip cone 52 from the slips 40 and to then permit the packing or sealing element 49 to return to its normal elongated position (Figure 5A). However, should packing elements 49 or the slips 40 be set in the casing W so that they cannot be released by a straight upward pull on the tubing T, a jarring blow can be applied to the lower end of the retaining sleeve 47 by initially rotating the tubing T to disconnect the threads 57 from the expansible nut 53 and thereafter urging upwardly on the tubing T to bring the latch ring 45 upwardly into sharp jarring engagement with the lower end of the sleeve 47. The jarring action can be repeated until the cone 52 is released and the sealing element 49 has returned to its normal undistorted position.

The upper packer B and the lower packer A are connected by a releasable connection C (Figure 50) which may be any suitable type of releasable connection, but as shown in the drawings, the releasable connection C is of the type that is adapted to be released by a rotation and upward pull on the tubing T, but is adapted to be set in connected position by a non-rotative downward movement of the tubing T. The mandrel 22 which extends upwardly from the lower packer A has threadedly connected therewith an inner J-slot sleeve 63. The J-slot sleeve 63 has one or more J-slots 63a formed therein for the purpose of receiving pins 64 which are welded or otherwise secured to springs 65. The springs 65 are mounted on an outer connecting sleeve 66 with screws 67 securing the lower ends. of the springs 65 so as to leave the upper end free to move outwardly from the position shown in Figure 5C. The outer sleeve 66 has openings 66a formed therein to permit the lateral sliding movement of'the pins 64 with respect to the outer sleeve 66. An adapter 68 connects the outer sleeve 66 to the mandrel 46 which extends downwardly from the upper packer B.

For releasing the releasable connection C, the tubing T is rotated to the left (as viewed from the top of Figure 5C) so as to move the pins 64 to the open portion of the J-slots 63a so that upon a non-rotative pavement line F from the surface of the well.

6 7 of the tubing T, the pins 64 slide freely from the slots 63a, whereby the outer sleeve 66 is moved upwardly and away from the inner sleeve 63. For reconnecting or reengaging the releasable connection C, the tubing string T is simply lowered without rotation and the pins 64 either slide into the slots 63a, or if they are misaligned, then the pins 64 will be expanded radially outwardly as they pass into the lower or horizontal portion of the slots 63a whereupon the springs 65 will urge them back into normal position so as to seat them within the lateral or horizontal portion of the slots 63a. In order to be certain that the pins 64 are in the lateral portion or leg of the J-slots 63a, the pipe is preferably rotated to the right after the straight downward movement of the tubing T.

The plug P for closing fluid flow through the lower packer A when such packer is in a set position, is illustrated in the latched position in Figure 6C and in the released position in Figure 7B. The inner sleeve 63 of the releasable coupling C has an inwardly extending annular latch shoulder 63b for engagement by latch levers 70 which are pivotally mounted at 71 to the body 72 of the plug P. Each latch lever 70 is urged radially outwardly by a spring 73 so as to position the latch shoulder 70a of each lever 70 under the annular latch shoulder 63b. A central pipe 75 extends longitudinally through the body 72 of the plug P and it is urged to a raised position (Figure 6) by a spring 76 located at its lower end and within a recess 72a in the body 72. Lateral ports 72b are provided in the body 72 for fluid communication with openings 75a in the pipe 75 when such openings 75a are aligned with the opening 72b. Such alignment occurs when the pipe 75 is forced downwardly against the force of the spring 76, as will be explained in connection with the retrieving tool. The upper part of the body 72 is formed with a relatively narrow diameter portion 72c which has downwardly extending buttress type teeth 72d formed on the external surface thereof. Such teeth 721! are used in the retrieving of the plug P from its latched position, as will beexplained. The plug P can be pumped or otherwise moved downwardly through the tubing string T and it will automatically be stopped against further downward movement when the lower annular shoulder 72e contacts the internal shoulder 63c in the inner latch sleeve 63. At that time, the latch levers 70 are permitted to move outwardly for engagement beneath the annular latch shoulder 63b on the sleeve 63 whereby the plug P is automatically latched against upward movement for closing off fluid flow through the bore of the lower packer A to the tubing string T.

One type of tool which is suitable for releasing and retrieving the plug P is illustrated in Figures 7A and 7B. The retrieving tool is designated by the letter R and it is adapted to be lowered on a wire line or other flexible The tool R includes a lower release cylinder 80 which is adapted to move downwardly and around the upper projections or dogs 7% on each of the levers 70 so as to retract the levers 70 from their extended position, whereby upon an upward movement the latch surfaces 70a are positioned inwardly from the collar or shoulder 63b so as to pass upwardly without obstruction by such shoulder 63b. A socket 81 is provided in the retrieving tool R so as to urge the pipe 75 downwardly against the spring 76, whereby the ports 72b and the opening 75a are aligned to equalize the pressure above and below the plug P to facilitate the retraction of the plug P. The socket 81 has provided therebelow an internally inclined conical surface 82 for receiving slip ring 83. Such slip ring 83 is split longitudinally and is adapted to expand and slide downwardly along the teeth 72d on the plug P as the tool R is lowered, but upon a raising of the tool R, the inclined surface 82 coacts to wedge the slip ring 83 tightly into contact with the teeth 72d so that the tool R cannot be released from the plug P. Since the latch levers 70 are held in a retracted position by the release cylinder 80, the plug P is readily removed from the well.

In the use of the apparatus disclosed in Figures SA-ll for carrying out the method of this invention, the ap paratus is initially lowered into the well casing W with a casing seal (Figure 1) of the usual casinghead surrounding the upper portion of the tubing T. The valve 91 on the tubing T at the surface of the well is closed to maintain control over fluid flow through the tubing T. The packers A and B are in their released or unset condition (Figures SA-SD) as the apparatus is lowered. When the apparatus has reached a predetermined point in the well casing W so that the lower packerA is positioned above the first formation X to be treated, the tubing T is then rotated to the right (clockwise as viewed from the top of Figure 1) so as to release the threads 23 from the coupling 25. The tubing T is then lowered to cause the cone 14 to expand the slips 10 into anchoring engagement with the well casing W; as the slips 10 are thus expanded, the upper threads 24 are engaged with the coupling or nut 25 by the downward non-rotative lowering of the tubing string T. The bypass ports 34 and 35 are also closed so that the differential in fluid pressure in the well casing acts to expand the sealing members 15 and 18 into sealing contact with the well casing W. Thus, the packer A is fully set or anchored in the wall casing W.

Thereafter, fluid is pumped from the surface of the well through the tubing T for treating the well formation X. The treatment may consist of acidizing, sand-fracing. squeezing cement or similar material, or any other well treatment (which may be desired). The apparatus is illustrated schematically in Figure 1 in the position for performing such well treating operations on the first formation X.

Assuming the well has been treated in any desired manner to cause the well fluid to flow or to improve the flow of well fluid from the well formation X, the formation X is then closed off to prevent fluid flow through the tubing by lowering the plug P through the tubing until it automatically latches itself in position for closing off fluid flow from the well formation upwardly through packer A (Figures 2 and 60). With the plug P in position, the connection C is released by a rotation of the tubing string T to the left to move the pins 64 out of the J-slots 63a and for permitting the upward m0vement of the tubing T while leaving the lower packer A in its set position in the well casing. Since the J-slot connection requires only a partial rotation for release, the threads 24 remain engaged Wiih'ihe coupling 25 to allow the lower packer to remain anchored in the well.

The release of the coupling C places the lower open end of the releasable coupling sleeve 66 in fluid communication with the next well formation Y to be treated. After the coupling C is released, the tubing T is moved upwardly a sufiicient distance to move the release sleeve 60 (Figure 5B) upwardly for an outward urging of the latch arms 44 to their release position. Thereafter, upon a downward movement of the tubing T, the latch ring 45 is moved past and below the latch arms 4450 that the cone 52 can be brought downwardly within the slips 40 for setting samc into gripping engagement with the well casing W. Continued lowering of the tubing T then causes the radial expansion or distortion of the sealing element 49 into sealing engagement with the well casing W. The extent of the movement of the tubing T for releasing the latch arms 44 and for setting the packer B is limited so that it is unnecessary to remove any lengths of pipe or tubing T at the surface of the well to effect the release and setting of the packer B, whereby the valve 91 remains on the tubing T to control fluid flow therethrough. The length of the pipe between the packers A and B is, of course,

9 A is located between the first formation X and the second formation Y. If such length of pipe between the packers was not predetermined in accordance with the lengths of the well formations and the distances therebetween, it is evident that the tubing T might have to be raised to such an extent to position the packer B above the well formation Y after the disconnection of the coupling C, that some length of pipe. would have to be removed at the derrick or well surface, thereby requiring the removal of the valve 91 and loss of control of fluid flow through the tubing T. Therefore, it is important thta the length of pipe between the packers be predetermined as above described so as to always have full control of the tubing T with the valve 91.

After the upper packer B is set, desired well operations such as the acidizing, sand-fracing and other similar well treating steps are performed by pumping fluid downwardly through the tubing and outwardly through the lower end of the coupling sleeve 66 as schematically indicated in Figure 2. It will be evident that such treating operation does not interfere with the well formation X which has been previously treated since the plug P and the packer A maintain the lower formation X closed ofi from the treating fluid. d

When the second well formation Y has been properly treated and is ready to produce oil or gas or other well fluid from that formation, the packer B is released from its set position by raising upwardly on the tubing T to release the slips 40 and the packing element 49 from their engagement with the well casing W. The movement of the latch ring 45 above the latch arms 44 permits arelatching of the slips 40 in the same position as when the device is lowered into the well casing W. Thus, the packer B can again be lowered or rotated without setting same.

The tubing T is then lowered to reconnect the coupling C, and the tubing is rotated to the right which causes the threads 24 to travel upwardly relative to the releasable nut 25 and be released therefrom. Then upon an upward raising of the tubing T, the threads 23 are caused to slide into engagement with the threads on the nut 25 by expanding the segments of the nut 25, as previously explained. Upon the re-engagement of the threads 23 with the coupling nut 25, the packer A again permits a bypass of the well fluid through the packer A and, of course, the slips 10 and the packing elements and 18 have been released from their set position. Thus, the entire apparatus can again be raised in the well so as to position the lower packer A above the well formation Y (Figure 3). The packer A is then set in gripping and sealing contact with the well casing W, as previously explained in connection with Figure 1 and thereafter the releasable coupling or connection C is disconnected and the upper packer B is set. It will be observed that the plug P remains in position during the upward movement of the apparatus to the position shown in Figure 3 for the treatment of the next well formation above the two previously treated well formations X and Y. The well formation Z is then treated, as previously explained in connection with the formations X and Y, and thereafter the coupling C is reconnected. The well formations X, Y and Z are then all in condition for the production of oil or gas therefrom, and it is desirableordinarily to' position the lower packer A above the last of the multiple formations which has been treated so that all of the fluid will be directed upwardly through the tubing T from all. of the formations.

However", it will be readily apparent that the apparatus can be usedv for selectively producing any one of the well formations by merely positioning the lower packer A below the formation to be produced and positioning the upper packer B above the formation to be produced, with the releasable connection C disconnected so that the oil or gas flowsupwardly between the packer through the tubing T. The plug P is removed if it is tified by the letter B.

desired to produce from below the lower packer A, but it is retained in position if it is desired toproduce between the packers A and B.

The retrieving apparatus R for removing the plug P has been previously described and such apparatus is lowered into the well tubing on the wire line or flexible support F for engaging and retrieving the plug P when such is desired.

Although the above described method is preferred, the method can be modified in numerous ways and still obtain the advantages of this invention. For example, the packers can be lowered with the plug P in latched position in the lower packer A so that the lower packer A would serve as a bridge plug since no fluid could flow past it when it was set.

Also, after the desired well formations have been 7 treated, the entire apparatus can be retrieved from the well and then heavy laden fluid or drilling mud can be used to kill the well while lowering production apparatus. If the apparatus of this invention is used for production after the treating steps, then only the lower packer A needs to be left in the well since the upper packer B could be removed and then tubing could be lowered and connected by connection C to the lower packer A. Other modifications of the method of this invention can be per- .formed within the scope of this invention.

From the above, it will also be evident that other types of packers and other types of connecting devices can be used other than those previously illustrated in connection with Figures 5A-ll. One example of another type of packer which can be used in place of the upper packer P is illustrated in Figures 12-15 and is iden- Modified construction of the lower packer A is illustrated in Figures 16A-16C and is identified by the letter A.

The modified lower packer A is identical with the lower packer A except that the pair of slip expanders 14 and 114 are utilized with slips 10 having a double inclined inner surface 10a and 10b so that the slips 10 are urged radially outwardly into gripping engagement with the well casing W as the slip expanders or cones 14 and 114 toward each other is permitted when the lower threads 23 have moved below the coupling 25 and the upper threads 24 are engaged therewith. The fluid pressure acting on the upper and lower sealing cups 15 and 18 urge the slip cones 14 and 114 toward each other. Also, the tubing weight can be applied to the cone 14 for urging same downwardly which results in a setting of the slips 10. The pin 29 extends into a slot 11a and a pin 129 extends into a slot 11b in the slip housing 11 so as to limit the longitudinal movement of the cones I 14 and 114 relative to the slips 10. The other parts its the modification of Figures 16A-16C are identical with those shown in Figure 5D and have like numerals.

In Figure 16A, the modified releasable coupling C is shown, wherein the J-slot construction illustrated in Figure 50 has been modified to provide an expansible nut connection which permits a release upon a rotation of the tubing and permits a reconnection or re-engagement of the connection C upon a non-rotative lowering of the tubing T. Such construction includes an inner lock or latch sleeve 163 which corresponds to the sleeve 63'- in Figure 5C, but instead of the J-slot 63a, the external surface of the sleeve 163 is provided with threads 1630 which are preferably righthand buttress threads and which have their upper portion inclined downwardly and their lower portion extending laterally. The threads 163a are adapted to engage a nut 164 which is formed of a plurality of arcuate segments which together make up a cylinder which are maintained in cylindrical shape by resilient rings 165. The latch sleeve 163 has theupper annular shoulder 1615b which is provided for the latching of a plug such as plug P previously described. The rest of the construction of the coupling C is substantially identical with the connection C and the operation is sub- 11 stantially identical, namely, the device is released by a rotation of the tubing string to the left and rare-engaged by a non-rotative lowering of the tubing string relative to the inner or latch sleeve 163.

In the modified packer B the mandrel 95 1S substituted for the mandrel 46 of the packer B and an enlarged central portion 95a is formed on the mandrel 95 with an upper shoulder 95b and a lower shoulder 95c. An annular recess 96 is formed at the central enlarged portion 96a of the mandrel 95 and entering grooves 96a and 96b are provided at the upper and lower ends of such recess 96.

The packer B has an upper pack ng or scaling element 98 and a lower packing or sealing element 99, with the upper sealing element 98 having pipe gripping members or segments 100 integrally connected therewith for radial movement into gripping engagement with the well casing W upon an expansion or distortion of the sealing element 98 upwardly. The lower packing or sealing element 99 has similar gripping members 101 formed therewith for movement radially outwardly into gripping contact with the well casing W when the packing element 99 1S radially expanded. The upper sealing element 98 is connected to a central body 102 by a coupling collar 103 which also carries internally a packing-ring 104 formed of rubber or other resilient material for engagement with the enlarged portion 95a when same is in the set or anchored position.

The lower sealing element 99 is likewise connected to the central body 102 through a coupling 105 and a packing ring 106 is carried internally of the coupling 105 for sealing engagement with the external surface of the enlarged portion 95a of the mandrel when the packer B is in the set position. The body 102 has a plurality of openings 102a formed therein for receiving latching lugs 108 which are secured to resilient spring members 109. The spring members 109 are connected by screws 110 or other suitable securing means at their upper ends to the body 102 so that the spring 109 in effect is pivotable or swingable about the screw 110 for urging the member 108 inwardly. When the spring 109 contacts the external surface of the body 102, the inward movement of the member 108 is, of course, stopped. The member 108 serves to contact the upper shoulder 95b as the packer B is lowered into the well casing W. With the member 108 in such contact with the latching shoulder 95b, the fluid seal rings 104 and 106 are out of contact with the mandrel 95 and a bypass of fluid is permitted through the bore of the packer B so that the fluid pressure does not act upon the sealing or packing elements 98 and 99 for setting same. However, when the packer is at the position for setting, the tubing or mandrel 95 is raised so as to cause the lugs 108 to travel through the upper entering grooves 96a into the annular recess 96 and then by rotation, the mandrel 95 is locked in position with the lug 108 therebetween. The seals 104 and 106 are thus in contact with the external surface of the enlarged portion 95a of the mandrel 95 to prevent a bypass of fluid so that the fluid pressure differential in the well casing then acts to urge the packing elements 98 and 99 radially outwardly into contact with the casing W. The gripping members 100 and 101 are also thus urged into gripping engagement with the well casing W. When it is desired to move the packer B upwardly, the mandrel 95 is rotated and the lug 108 is caused to travel through the lower entering groove 96b and thereafter contact is made with the lower shoulder 950. It will be appreciated that the reduced diameter portion of the mandrel 95 is not in contact with the seal rings 104 and 106 so that there then is a bypass of the fluid to the bore of the packer as the packer is raised in the well casing W, whereby the packing elcments 98 and 99 are prevented from being urged into sealing contact with the well casing W.

It is believed evident that the construction of the modias one apparatus or the modified packers could be substituted as desired for the packers illustrated in thepreferred form of the invention. In any event, it is, believed apparent that neither the apparatus nor the method of the invention is limited to any particular type of packing construction or any particular type of releasable connection between the packers.

The foregoing disclosure and description of the invention is illustrative and explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made within the scope of the appended claims without departing from the spirit of the invention.

What is claimed is:

1. A well apparatus including, a tubing lowerable into a well bore to extend therethrough, an upper packer including an upper packer mandrel and packer element mounted on the tubing, a lower well packer including a lower packer mandrel and packer element mounted upon said tubing and longitudinally spaced from the upper packer, said upper and lower packer mandrels forming a continuation of the tubing, said tubing being utilized to position the packers within the well bore, a releasable connecting means between the upper and lower mandrels, said lower packer including co-acting means between the lower packer element and the lower packer mandrel and operable by manipulation of said tubing to set or release the lower packer, said upper packer including co-acting means between the upper packer element and the upper packer mandrel and operable by manipulation of said tubing to set or release the upper packer, the releasable connecting means being operable by manipulation of the tubing whereby the upper packer may be moved upwardly with respect to the lower packer after said lower packer is set, said releasable connecting means being subsequently re-connectible to again connect both packers to the tubing, whereby the selective setting and releasing of said packers is under the control of saidtubing.

2. A well apparatus as set forth in claim 1 wherein the co-acting means between the lower packer element and the lower packer mandrel includes means for locking the lower packer against setting, and means actuated by a rotation and lowering of the tubing relative to the lower packer for releasing the locking means to permit setting of said lower packer.

3. A well apparatus as set forth in claim 1 wherein the co-acting means between the lower packer element and the lower packer mandrel includes means for locking the lower packer against setting, and means actuated by a rotation and lowering of the tubing relative to the lower packer for releasing the locking means to permit setting of said lower packer, the co-acting means also including means for locking the lower packer in set position with this latter means being actuated by a downward-movementof the tubing to lock said lower packer in set position and being actuated by arotation of said tubing and upward movement thereof relative to the lower packer to unlock the packer from set position.

4. A well apparatus as set forth in claim 1, wherein the coacting means between the lower packer element and the lower packer mandrel comprises a threaded coupling member carried by the lower packer element and a pair of longitudinally spaced threaded sections on the lower packer mandrel, engagement of the lower thread section with the coupling member locking the lower packer against setting and disengagement of said lower thread section from the coupling member unlocking said lower packer to allow it to move to set position, the engagement of the upper thread section on the mandrel with the coupling member locking the lower packer in its set position.

5. A well apparatus as set forth in claim 1, wherein the eo-acting means between the lower packer element and the lower packer mandrel comprises a threaded coupling ment of the upper thread section on the mandrel with the coupling member locking the lower packer in its set position, means for disengaging the lower thread section from the coupling member by a rotation of the tubing and for re-engaging said section with the member by a direct upward movement of the tubing, means for engaging the 'upper thread section on the tubing with the coupling member by a direct downward movement of the tubing and for disengaging said upper thread section from the tubing by a rotation of the tubing relative to the lower packer.

6. A well apparatus as set forth in claim 1, wherein the co-acting means between the lower, packer element and the lower packer mandrel comprises a threaded coupling member carried by the lower packer element and a pair of longitudinally spaced threaded sections on the lower packer mandrel, engagement of the lower thread section with the coupling-member locking the lower packer against setting and disengagement of said lower thread section from the coupling member unlocking said lower packer to allow it to move to set position, the engagement of the upper thread section on the mandrel with the coupling member locking the lower packer in its set position, means for disengaging the lower thread section from the coupling member by a rotation of the tubing and for re-engaging said section with the member by a direct upward movement of the tubing, means for engaging the upper thread section on the mandrel with the coupling member by a direct downward movement of the tubing and for disengaging said upper thread section from the mandrel by a rotation of the tubing relative to the lower packer, the direction of rotation of the tubing which effects the disengagement of the lower thread section from the member and which efiects disengagement of the upper thread section being the same in both instances.

7. A well apparatus as set forth in claim, 1, wherein' the co-acting means between the upper packer element and the upper packer mandrel includes a latching means carried by the upper packer element and engageable with the upper packer mandrel for latching the upper packer against setting, and means mounted on the upper packer mandrel and operable upon an upward movement of the tubing relative to the upper packer element for releasing said latching means to permit setting of the upper packer by a relative downward movement of the tubing with respect to said upper packer element.

8. A well apparatus as set forth in claim 1, wherein the co-acting means between the upper packer element and the upper packer mandrel includes a latching means carried by the upper packer element and engageable with the upper packer mandrel for latching the upper packer against setting, and means mounted on the upper packer mandrel and operable upon an upward movement of the tubing relative to the upper packer for releasing said latching means to permit setting of the upper packer element by a relative downward movement of the tubing with respect to said upper packer element, said latching means being positioned to again latch the upper packer against setting upon a subsequent upward movement of the tubing from a position in which the upper packer is set.

9. In subsurface well apparatus for applying pressure within a well bore, a well tubing string lowerable into said bore, an upper removable well packer carried by the tubing string and having an upper packer mandrel providing a continuation of said tubing string and having longitudinal movement of the string relative to the packer element for anchoring the packer within the bore, a lower removable well packer having a lower tubular mandrel extending therethrough, a releasable connection means connecting the lower end of the upper packer mandrel to the upper end of the lower packer mandrel, said lower packer having means operated by rotation of the lower mandrel in one direction for anchoring the packer within said bore, and means within said releasable connection for releasing the same to disconnect the tubing string from the lower mandrel after the lower packeris in anchored position, said last-named means being operable by a partial rotation of the'tubing string in a direction opposite that required to operate the anchoring means of said lower packer, the upper packer being movable to anchored position by longitudinal movement of the tubing string relative to the upper packer element subsequent to release of the releasable connection means and separation of the tubing and lower mandrel.

10. In subsurface well apparatus as set forth in claim 9, together with a removable plug lowerable through the tubing string into the lower mandrel prior to separation of the string and lower mandrel, and co-acting means on said plug and within said lower mandrel for latching said plug in position closing off fluid flow through the lower mandrel.

11. In subsurface well apparatus as set forth in claim 9, wherein the upper packer includes co-acting means on the upper packer mandrel and upper packer element for preventing relative movement of the string and packer element while the releasable connection means is connecting said string and lower mandrel, said co-acting means being actuated by manipulation of the tubing string after the connection means is released to render inoperative said co-acting means to thereafter permit the upper packer to be anchored.

12. A method of completing a well having multiple formations, comprising the steps of, lowering a pair of packers into a well bore on a tubing, setting the lower of said packers in the well bore between an upper and a lower well formation to be treated, treating said lower well formation which is below said lower packer by flowing fluid downwardly through the tubing and through said lower packer, then closing flow through said lower packer, thereafter disconnecting the lower packer from the upper packer and tubing, raising the upper packer to communicate the lower end of the upper packer with the upper well formation to be treated, then setting the upper of the packers above said upper well formation, thereafter treating said upper well formation by flowing fluid through the tubing for discharge from the end of the upper packer adjacent said well formation, releasing the upper packer from its set position after such treating of the well formation, then reconnecting the tubing and upper packer with the lower packer, releasing the lower packer from its set position in the well bore and then moving said packers to another longitudinal position within the well bore.

13. The method of treating a well having lower and upper well formations comprising the steps of, lowering a pair of well packers into the well bore on a well pipe, anchoring the lower of the well packers within the well above the lower well formation and below the upper well formation, pumping fluid through the well pipe and through the lower packer to said lower well formation below the lower packer, thereafter closing the flow passage through the lower packer to completely close fluid flow to and from said lower formation, then positioning and anchoring the upper well packer in the well bore above the upper well formation, and thereafter pumping fluid through the well pipe and upper packer and directing it to said upper well formation.

'14. The method as set forth in claim 13 together with the additional step of subsequently opening the flow a packer element, said packer having means operated by passage through the lower packer to permit fluid flow 1 from the lower formation upwardly through said lower ker. :5. The method as set forth in claim 13 together with the additional steps of subsequently opening the flow passage through the lower packer, releasing the upper packer from anchoring position, releasing the lower packer from anchoring position and then moving both packers to other longitudinal positions in the well.

16. A method of treating a well having multiple formations, comprising the steps of lowering a pair of well packers into the well bore on a well plpe, anchoring the lower of the well packets in the well bore above one of the well formations, then pumping fluid through the well pipe to the area below the lower packer for treatmg said one of the well formations, thereafter lowenr 1g a plug through the well pipe and latching the same within the bore of the lower packer to close the bore of said lower packer, disconnecting the lower packer from the well pipe and the upper packer, then positioning the upper well packer above a second well formation which is located above the aforesaid one formation and setting the same in the well bore, and thereafter treating the second well formation while said lower packer prevents the treating fluid from passing below into the first of the formations treated.

References Cited in the file of this patent UNITED ST ATBS PATENTS 2,051,713 Howard Aug. 18, 1936 2,114,373 Edwards Apr. 19, 1938 2,122,749 Morrisett July 5, 1938 2,163,976 Edwards et al. June 27, 1939 2,189,701 Burt et al. Feb. 6, 1940 2,327,092 Botkin Aug. 17, 1943 2,368,400 Baker Jan. 30, 1945 2,368,428 Saurenman Jan. 30, 1945 2,373,034 Laird et al. Apr. 3, 1945 2,378,469 Denton June 19, 1945 2,429,910 Anderson et a1. Oct. 28, 1947 2,644,524 Baker July 7, 1953 2,650,664 Sorensen Sept. 1, 1953 2,806,532 Baker et a1. Sept. 17, 1957 2,893,492 Brown July 7, 1959 

